GCC 4.6.1 was the latest stable GNU Compiler Collection release
at the time of testing (GCC 4.6.2 is now available with various bug-fixes). GCC
4.7-20111015 was the latest snapshot for GCC 4.7.0 available at the time of testing,
which is still in stage one of development and will be officially released in
the next few months. LLVM/Clang 3.0 is being officially released in early November
and the tested SVN revision is a near-final version of this Apple-sponsored compiler
infrastructure that is becoming immensely popular. Open64 4.2.4 is the latest
open-source Open64 release available from the project's web-site while there is
an Open64 4.2.5.2 release available from AMD's web-site that offers more Bulldozer
optimizations, among other work.

The GCC releases were built with --enable-release=checking
and LLVM/Clang was compiled with --enable-optimized and --disable-assertions,
to mirror release builds. The Open64 compilers were using the 64-bit binaries.

With each different compiler tested, the Phoronix
Test Suite rebuilt all of these C/C++ benchmarks each time before execution.
The rest of the system stack remained the same. For this article, all tests were
built with their stock compiler flags, but in another Bulldozer compiler article
is a look at compiler tuning for Bulldozer-specific optimizations along with other
flags.